mlxsw: Fix mlxsw_i2c_write return value

The "err" variable is been checked, return always 0.
Signed-off-by: Elad Raz <eladr@mellanox.com>
Acked-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/i2c.c

@@ -338,7 +338,7 @@ mlxsw_i2c_write(struct device *dev, size_t in_mbox_size, u8 *in_mbox, int num,
 		return -EIO;
 	}
 
-	return err > 0 ? 0 : err;
+	return 0;
 }
 
 /* Routine executes I2C command. */